The Planetary Accretion Shock. III. Smoothing-free 2.5D Simulations and Calculation of Hα Emission

Autor: Gabriel-Dominique Marleau, Rolf Kuiper, William Béthune, Christoph Mordasini

Publikováno v: The Astrophysical Journal, Vol 952, Iss 1, p 89 (2023)

Surveys have looked for H α emission from accreting gas giants but found very few objects. Analyses of the detections and nondetections have assumed that the entire gas flow feeding the planet is in radial freefall. However, hydrodynamical simulatio

Externí odkaz: https://doaj.org/article/974adaa2f92b480eabf5f253b7f38bc3

Migration of Jupiter-mass planets in low-viscosity discs

Autor: D. Kloster, H. Méheut, Alessandro Morbidelli, Richard P. Nelson, A. Crida, Alexandros Ziampras, William Béthune, Willy Kley, Elena Lega, Thomas Rometsch

Publikováno v: Astronomy and Astrophysics-A&A
Astronomy and Astrophysics-A&A, EDP Sciences, 2021, 646, pp.A166. ⟨10.1051/0004-6361/202039520⟩

Type-II migration of giant planets has a speed proportional to the disc's viscosity for values of the alpha viscosity parameter larger than 1.e-4 . At lower viscosities previous studies, based on 2D simulations have shown that migration can be very c

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::05c53fe58f5e882938fd6496e3930c7d
https://hal.archives-ouvertes.fr/hal-03154032/document

Migration of Jupiter mass planets in discs with laminar accretion flows

Autor: Richard P. Nelson, Alessandro Morbidelli, X. S. Ramos, A. Crida, Konstantin Batygin, William Béthune, Elena Lega

Publikováno v: Astronomy and Astrophysics-A&A
Astronomy and Astrophysics-A&A, EDP Sciences, In press, ⟨10.1051/0004-6361/202141675⟩
Lega, E, Morbidelli, A, Nelson, R P, Ramos, X S, Crida, A, Béthune, W & Batygin, K 2022, ' Migration of Jupiter mass planets in discs with laminar accretion flows ', Astronomy and Astrophysics, vol. 658, A32 . https://doi.org/10.1051/0004-6361/202141675

Migration of giant planets in discs with low viscosity has been studied recently. The proportionality between migration speed and the disc's viscosity is broken by the presence of vortices that appear at the edges of the planet-induced gap. Our goal

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::83ccc7971b1f0d603998ef0bcb067511
https://hal.archives-ouvertes.fr/hal-03472360

Self-gravitating planetary envelopes and the core-nucleated instability

Autor: William Béthune

Planet formation scenarios can be constrained by the ratio of the gaseous envelope mass relative to the solid core mass in the observed exoplanet populations. One-dimensional calculations find a critical (maximal) core mass for quasi-static envelopes

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e443a98e951b4620848116dbaa4f1b9f

Order out of Randomness: Self-Organization Processes in Astrophysics

Autor: Mark C. M. Cheung, Markus J. Aschwanden, Juergen Kurths, D. Mueller, Jeffrey D. Scargle, W. H. Green, Alexei G. Kritsuk, William Béthune, Arnold O. Benz, Werner Schmutz, Felix Scholkmann, Andrew Melatos, Guennadi Chernov, V. I. Abramenko, Virginia Trimble, Robert V. Wagoner

Publikováno v: Space Science Reviews, 214
Aschwanden, Markus J; Scholkmann, Felix; Béthune, William; Schmutz, Werner; Abramenko, Valentina; Cheung, Mark CM; et al.(2018). Order out of Randomness: Self-Organization Processes in Astrophysics. Space Science Reviews, 214(2). doi: 10.1007/s11214-018-0489-2. UC Irvine: Retrieved from: http://www.escholarship.org/uc/item/4tf8h889
Web of Science

Self-organization is a property of dissipative nonlinear processes that are governed by a global driving force and a local positive feedback mechanism, which creates regular geometric and/or temporal patterns, and decreases the entropy locally, in co

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::87b6e7fde506bfd3d8b5a13bcae83c26